When selecting my embark location, I tend to check the following things:
Brook/River: As long as we are required to muddy the soil before putting farms around, the water source is required. Now, usually murky pools do the same thing, though if one has turned weather off from init.txt (as I do the get some more precious FPS and due lethal rain), one can't trust them.
One level of soil: In 40d I tend to find a site with two to four soil layers, two as minimum. This is because mining soil level is faster and first floor is usually dedicated to military and trading, so farms had to go to floor 2. Now, due the farming thing mentioned in brook/river section, I'm forced to muddy the floor anyway, so one layer of soil is enough.
Sand: Yes, you can import sand from traders, but they don't usually bring much, or at least in my experience, so you basically need sand layer to support heavy glass making. Personal opinion, though.
Aquifer: I usually turn aquifers off from raws, so those don't bother me. If, for some strange reason, I have to run a game with aquifers on, I tend to choose location without it. Though the requirement for muddy soil could justify me to embark with aquifer.
I don't usually bother with stone layers, though one with possibility (right now that means certain) for iron ore is plus.
For skills, I have begun prefer following composition:
Miner/Leader
Miner/Broker
Miner/Bookkeeper (will become arsenal noble when necessary, as both seems to use the same skill(s))
Miner/Sheriff
Miner/Military leader
Miner/Medical leader
Woodcutter/Farmer
The idea behind this setup is that all those miners will dig the layout of my fort, which usually takes time as many things must be completed fast enough. Those include area for farming, stockpiles (wood industry, trading goods industry, stone industry and metal industry) and related necessary workshops. Also area for housing, hospital, barracks, studies, grand dining room and personal dining rooms. The woodcutter/farmer cut trees to the point where first farm plot can be established.
Now, for items, the only requirements I have is enough food and booze to survive to the point when first immigrant wave arrives. As this usually happens very fast, I can get most things running quite soon. Until that, no brewing unless I desperately need. That's why enough booze.
Other than that, the specific selection of items doesn't matter, as you can create world with using parameters, and there you can change the amount of embarking points, thus making micromanaging unnecessary. Though because of that there is no reason to embark without at least one anvil. This is because traders don't always bring anvils anymore, or so I have seen. This is probably due the fact that traders don't come with wagons at the moment.
For animals, two war dogs (both male) and cat (male).
Lastly, this pretty much matter of opinion and how you want to run your fortress, but I usually embark with at least 20 small cut gems. When I have enough dwarves to support jewel industry (which is usually around 14 dwarves, which basically means right after first wave of migrants) I tend to begin encrusting either my trading goods or my furniture with gems.